Just wondering if anyone had any input on this. As far as I can tell the answer is near zero.

From
http://www.globalsecurity.org/wmd/wo...an/bushehr.htm

It sounds like a plant like Iran is making could produce enough plutonium for 30 bombs per year. What is required to get the right plutonium amount is to pull the fuel rods at ~4 months instead of leaving them in longer.

However, depending on how they rotate the fuel rods, that means that there could be up to 10 nukes worth of plutonium just sitting there. That number being for putting all rods in at the same time, waiting until they reached the desired time period and then pulling them.

The rest of the project could have been done elsewhere. For a simple implosion type device it's simply a matter of getting the stuff in the cores turned into balls. That process is what I have no idea about.

Otherwise it sounds like you have minutes to hit a nuclear power plant if fuel is being taken out to stop it. Probably impractical if not impossible to do. Then you have some small amount of time to locate and destroy wherever the final refinement is taking place before the country in question becomes a nuclear power.

Maybe a couple days?

It depends on the type of reactor and the type of fuel rod. IOW, fast flux reactors like the newest one at Hanford does not necessarily create plutonium. The original reactors at Hanford for example created trace amounts of plutonium as a byproduct of the nuclear chain. So, yes, the fuel rods may have plutonium in them, but the process to isolate the plutonium involves something like 15 highly radioactive and incredibly caustic steps. The buildings at Hanford used for plutonium separation are essentially sealed for thousands of years with automated, integrated, and self-sufficient processes never meant to have a human any where near them. That was how they were designed in the early 40's. The point is, it is not really a simple task to isolate the plutonium, plus, it tends to decay into other elements thus "poisoning" its fissile qualities rather quickly--especially compared to uranium 235.

The other aspect of your post was the simplicity of creating the cores. You have to understand that the way the implosion device works is by taking a sub-critical amount of fissile material in a given volume, and turning it into a super-critical amount of fissile material of the same amount in a much smaller volume. This is really no easy task. They pulled this off at the trinity test in New Mexico for the first time. The way they did it was by using "lenses" of high explosive joined with shapes of low yield explosive. The idea was to completely turn a shockwave inside-out (an uninterrupted shock wave gets larger from its epicenter) and focus it in three dimensions literally inside its epicenter on a sphere of low-density plutonium, crushing the sphere to a volume that created a super-critical mass. When Oppenheimer described the physical challenges created in this problem, he likened it to crushing a beer can without spilling a drop.

These are just a few highlights of the challenges that they faced in the Manhattan Project. I think it is harder than you imagine to make an atomic bomb. The refinement of the fissile material is especially tedious, expensive, slow, and deadly. If you want to look at photos or read more about either gaseous diffusion or plutonium separation, look up Hanford, Washington, (AKA Manhattan Project, plutonium separation) or Oakridge, Tenessee. (AKA Site X Gaseous Diffusion, isotope separation.)

Anyway, there you go. Something to think about...

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We should take them out now.

Good info. (though good links with indications of time will get you rep )


However I disagree on the "difficult to make the cores" issue. I don't know the exact details, but it sounds like the Nth Country Experiment shows that it isn't that hard to work out.

And a lot of stuff has been declassified and a number of countries have the knowledge. I doubt it's that hard to get.

So it really comes down to the time between when they shut down the reactor to pull the plutonium to the time they can shape a batch of weapons grade plutonium. I suppose it took N Korea a while. But they were a nation in serious fininacial straights. Iran is not. Also Korea seems like to sort of went forward to nuclear weapons in starts and fits as opposed to workout and prepare everything ahead of time except the plutonium.

Well, thanks. Believe it or not, that was all off the top of my head, so, here's my link: http://www.metro'sbrain.com/stuf...tsomehowstuck/

The best book you will ever find on this subject and the one we studied before we went to Hanford (bar-none the most amazing place I have ever seen) is called "The Making of The Atomic Bomb" by Richard Rhodes. It won a Pulitzer Prize, and is absolutely amazing if you know basic chemistry and basic physics.

Interesting link. Thanks for that. According to your link, the Nth Country Experiment deals only with design, not with procurement, which was the thrust of my post. Nevertheless, that was a good link.

From your link:

As it says in your Nth Country link, the information is out there, I don't deny that. The technology for a Uranium 235 Weapon is crude, but separating the U235 from the heavier U238 is absolutely daunting because they are chemically indistinguishable and identical except for their atomic weight as you hopefully saw if you looked for "Site X" Gaseous Diffusion work at Oakridge. Clearly the issue is the actual work to get pure fissile material of the quality necessary to create a fast enough chain reaction that you get yield.

As I said, it is not shaping the plutonium but isolating it. And, it is important to understand what type of reactor and rod is being used because at Hanford, where the only point was to create plutonium for bomb material, they were creating hardly more than trace amounts per rod. It took them years to get enough plutonium for a few weapons. Having said that, it was almost 70 years ago, so I'll concede that science has made some improvements. The basic chemistry remains, the physics remain.

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The link in my first post says that Irans reactor, for example, could produce 30 bombs per year. Whatever that exactly means. And indicates that what is required is simply to pull the cores out early to get a good plutonium blend.
Again from the time in there you should be able to pull up to 10 bombs worth of plutonium out at once if you shut down the reactor.

So it's a matter for seperating the Uranium and other products from the weapons grade plutonium. How fast is that? I dunno. But Plutonium is a different element, not just a different isotope. So it might be easier than regular uranium refinment.

I'll go look more closely...

Certainly separating elements is way easier than separating isotopes, but again, separating plutonium from spent uranium rods is not easy either. I'll have a closer look at your link. Did you find anything interesting on Oakridge or photos of the "Queen Marys of the Desert" at Hanford?

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Ok, had a closer look at your Globalsecurity link...


In my estimation of that article, they are farther away than you think.

One aspect is the Plutonium isotope issue addressed here:

There is a lot of critical information missing in this article that would help to really explain what a timeline may look like. First, it doesn't say how much plutonium is created per fuel rod, only the percentage of usable 239 in a given timeframe. This ties directly into the next aspect of the equation, which is that they receive their fuel rods from Russia, and are supposed to return the spent rods. Obviously that could change, but since they don't have in-country access to uranium rods at the moment, their potential weapons inventory is limited to Russian rod output. As of the writing of the article, it says they have 180 rods, and no way to do the chemical separation. --A major, major hurdle as we have previously discussed. This also begs the critical question of how many rods a reactor head needs to function. A rod at Hanford has a life span of 2 years. The rods are rotated out on some sort of schedule so the head always has a average power output (i.e., the head has old, medium, and new rods in it any time). Since we don't know the capacity of the reactor in Iran or the amount of plutonium created per rod, we have no idea what the actual plutonium output is. Moreover, the plutonium output is directly related to the efficiency of the head-- if you don't have new rods to drive the reaction, the existing Pu is poisoned by its own isotopes by waiting too long.

I hope this makes sense. If I need to explain some part of it more clearly, let me know...

The second, and really unaddressed aspect of the article is the lack of separation facility. I know this sounds simple, but it really is a huge hurdle that must be crossed. First, Iran must have access to its own supply of fuel rods, and second, it must have the technology and impetus to do so. These are daunting.

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Articles on N Koreas nuclear program don't mention new facilities for plutonium refienment.

Is there any reason to believe the material from the rods couldn't be fed into existing Uranium enrichment equipment? Except that it would be much more efficient due to the now larger mass difference of the products?

As for the time, what I understood is what you said. You spoil your Pu if you leave it in the reactor too long. So it would be a matter of yanking a number of rods rods when they are read. My 10 number comes from being able to make 30 bombs from rods that take 4 months. So if you started all the rods at once and pulled them you should get 10 bombs. Of course the actually number should be less than this. But even 3 bombs might be "enough". One to test, two to threaten.

These links are both photos and good explanations of what we've been discussing.

Plutonium Separation at Hanford

Oak Ridge

Explanation of Calutrons and atom-by-atom separation of U235 and U238 at Oak Ridge.

Ponder that: atom by atom to build a bomb...

B Reactor at Hanford

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